Spring Boot —Mybatis整合

一.导入依赖

 <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.1.6.RELEASE</version>
  </parent>
  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
  </properties>

  <dependencies>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-configuration-processor</artifactId>
      <optional>true</optional>
    </dependency>
    <!-- servlet依赖. -->
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>javax.servlet-api</artifactId>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>jstl</artifactId>
    </dependency>

    <!-- tomcat的支持.-->
    <dependency>
      <groupId>org.apache.tomcat.embed</groupId>
      <artifactId>tomcat-embed-jasper</artifactId>
      <scope>provided</scope>
    </dependency>

    <!-- mybatis -->
    <dependency>
      <groupId>org.mybatis.spring.boot</groupId>
      <artifactId>mybatis-spring-boot-starter</artifactId>
      <version>1.3.2</version>
    </dependency>
    <!-- mysql -->
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>5.1.22</version>
    </dependency>
    <!--分页-->
    <dependency>
      <groupId>com.github.pagehelper</groupId>
      <artifactId>pagehelper-spring-boot-starter</artifactId>
      <version>1.2.3</version>
    </dependency>
    <!--sprinboot 测试-->
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-test</artifactId>
    </dependency>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
    </dependency>
    <!--热部署-->
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-devtools</artifactId>
      <optional>true</optional>
      <scope>true</scope>
    </dependency>

  </dependencies>

  <build>
    <plugins>
      <plugin>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-maven-plugin</artifactId>
      </plugin>
    </plugins>
  </build>

二.设置定义启动类

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;

@SpringBootApplication
//@MapperScan可以指定要扫描的Mapper类的包的路径
@MapperScan("cn.mapper")
//@ComponentScan告诉Spring 哪个packages 的用注解标识的类 会被spring自动扫描并且装入bean容器。
@ComponentScan("cn")
public class SpringBootSSm {
    public static void main( String[] args ) {
        SpringApplication.run(SpringBootSSm.class  ,args) ;
    }
}

三.springboot核心配置文件

application.yml

spring:
  datasource:                      #数据库连接池
    driver-class-name: com.mysql.jdbc.Driver
    username: root
    password: root
    url: jdbc:mysql:///student
  mvc:
    view:
      suffix: .jsp
      prefix: /WEB-INF/views/

pagehelper:                #分頁
  helperDialect: mysql
  reasonable: true
  params: count=countSql

四.代码编写

特别注意的是 编写代码时候 必须是在启动类为子侄级别，不可超过启动类包所在级别

例如 启动类在cn.leilei.SpringBootSSm 那么代码编写必须是在cn.leilei.xxx包.xxx之下

同样可以使用generator生成domain ,mapper 以及对应的mpper.xml

domain

public class Student {
    private Long id;
    private String name;
    private String nikeName;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getNikeName() {
        return nikeName;
    }

    public void setNikeName(String nikeName) {
        this.nikeName = nikeName;
    }

    @Override
    public String toString() {
        return "Student{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", nikeName='" + nikeName + '\'' +
                '}';
    }
}

mapper

Component标签在这 只是特别再次抢到告诉spring你可以扫描他成为bean，防止其他地方Autowired 注入时候报红（假红)没有其他实际作用 ，，

@Component
public interface StudentMapper {
    List<Student> selectAll();
}

mapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="cn.mapper.StudentMapper" >
    <resultMap id="BaseResultMap" type="cn.domain.Student" >
        <id column="id" property="id"  />
        <result column="name" property="name"  />
        <result column="nike_name" property="nikeName"  />
    </resultMap>

    <select id="selectAll" resultMap="BaseResultMap" >
        select id, name, nike_name from student
    </select>
</mapper>

service

public interface IStudentService {
    List<Student> selectAll();
}

service.impl

@Service
@Transactional
public class StudentServiceImpl implements IStudentService {

    @Autowired
    private StudentMapper studentMapper;

    @Override
    //@Transactional(readOnly = true)
    public List<Student> selectAll() {
        return studentMapper.selectAll();
    }
}

controller

package cn.controller;


import cn.domain.Student;
import cn.service.IStudentService;
import com.github.pagehelper.PageHelper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;

import java.util.List;
@Controller
@RequestMapping("/stu")
public class StudentController {

    @Autowired
    private IStudentService studentService ;

    @RequestMapping("/list")
    public String  findall(Model model){
        List<Student> students = studentService.selectAll();
        model.addAttribute("students", students);
        return "student";
    }

    @RequestMapping("/listpage")
    public String  findallpage(Model model){
        //调用Mybatis自带的分页方法进行分页，，如果有需要则自己根据mybatis分页方法返回对象数据封装为自己的分页对象返回给前台
        PageHelper.startPage(0, 3);
        List<Student> students = studentService.selectAll();
        model.addAttribute("students", students);
        return "student";
    }
}

webapp/WEB-INF/views/student.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
         pageEncoding="UTF-8"%>

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>

<table align='center' border='1' cellspacing='0'>
    <tr>
        <td>id</td>
        <td>姓名</td>
        <td>昵称</td>
    </tr>
    <c:forEach items="${students}" var="s" varStatus="st">
        <tr>
            <td>${s.id}</td>
            <td>${s.name}</td>
            <td>${s.nikeName}</td>
        </tr>
    </c:forEach>
</table>

这里只是简单的在webapp集成了下，其他集成或者在resource下集成，后续更新。